DEBINDING　MECHANISM　AND　KINETICS　FOR　PW　IN　PW－WC　FEEDSTOCK　UNDER　AIR　ATMOSPHERE

ＤＥＢＩＮＤＩＮＧＭＥＣＨＡＮＩＳＭＡＮＤＫＩＮＥＴＩＣＳＦＯＲＰＷＩＮＰＷ－ＷＣＦＥＥＤＳＴＯＣＫＵＮＤＥＲＡＩＲＡＴＭＯＳＰＨＥＲＥＬｉａｎｇＳｈｕｑｕａｎ；ＨｕａｎｇＢａｉｙｕｎ；ＱｕＸｕａｎｈｕｉ（ＮａｔｉｏｎａｌＬａｂｏｒａｔｏｒｙｆｏｒＰ...

The feedstock, a binder-powder plastic body consisting of paraffin wax (PW) and WC powder, is of great importance for hard metal injection molding (MIM) and extrusion processing. The debinding mechanism and kinetics for a specific PW-WC feedstock under air atomsphere have been investigated in terms of the experimental results of differential thermal analysis (DTA) and thermogravimetric analysis (TGA).The investigations have shown that it is a very complex chemical and physical process, in which the paraffin wax ketonization and the sublimation of both the binder and the binder ketonization products are involved.The kinetic behavior obeys one order reaction law, with activation energies of 60. 1 kJ·mol-1 and 95. 6 kJ·mol-1 for PW system and PW-WC feedstock system respectively.